Genetic localization of the familial adult myoclonic epilepsy (FAME) gene to chromosome 8q24

Objective: To identify the genetic locus for the familial adult myoclonic e pilepsy (FAME) gene. Background: Idiopathic generalized epilepsy (IGE) repr esents a collection of disorders in which affected individuals present with recurring seizures that have diffuse onset on EEG. These individuals have no known structural cerebral lesions or other identifiable etiology. IGE ac counts for approximately 40% of all epilepsies. FAME is a type of IGE chara cterized by autosomal dominant inheritance, adult onset, varying degrees of myoclonus in the limbs, rare tonic-clonic seizures, and a benign course. M ethods: We investigated four previously reported Japanese kindreds and perf ormed a genome-wide screen with genetic linkage analysis. Results: Clinical characterization and sampling of 30 individuals in four families revealed that 21 had the FAME phenotype. We defined a 4.6-cM region on chromosome 8q 24 (maximum lod score of 4.86 at O = 0) that contains the FAME gene. Conclu sions: The identification and characterization of the FAME gene allows us t o better understand the molecular basis of FAME. Such knowledge may provide clues to understanding the molecular basis of the clinically similar, and more common, juvenile myoclonic epilepsies, and other generalized seizure d isorders that have thus far eluded genetic approaches.